In a typical cellular system, also referred to as a wireless communications network, wireless terminals, also known as mobile stations and/or user equipment units communicate via a Radio Access Network (RAN) to one or more core networks. The wireless terminals can be mobile stations or user equipment units such as mobile telephones also known as “cellular” telephones, and laptops with wireless capability, e.g., mobile termination, and thus can be, for example, portable, pocket, hand-held, computer-comprised, or car-mounted mobile devices which communicate voice and/or data with radio access network.
The radio access network covers a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g., a Radio Base Station (RBS), which in some networks is also called “NodeB” or “B node” or “Evolved NodeB” or “eNodeB” or “eNB”. A cell is a geographical area where radio coverage is provided by the radio base station equipment at a base station site. Each cell is identified by an identity within the local radio area, which is broadcast in the cell. The base stations communicate over the air interface operating on radio frequencies with the user equipment units within range of the base stations.
In some versions of the radio access network, several base stations are typically connected, e.g., by landlines or microwave, to a Radio Network Controller (RNC). The radio network controller, also sometimes termed a Base Station Controller (BSC), supervises and coordinates various activities of the plural base stations connected thereto. The radio network controllers are typically connected to one or more core networks.
The Universal Mobile Telecommunications System (UMTS) is a third generation (3G) mobile communication system, which evolved from a second generation (2G) communication system—the Global System for Mobile Communications (GSM). UMTS Terrestrial Radio Access Network (UTRAN) is essentially a radio access network using wideband code division multiple access for user equipment units (UEs). Long Term Evolution (LTE) together with Evolved Packet Core (EPC) is a fourth generation (4G) mobile communication system.
LTE is a packet based IP network that does not support Circuit Switched (CS) calls. Circuit Switched Fallback (CSFB) is a technology that allows voice services to be delivered to LTE devices through the use of GSM or another CS network. When an LTE device needs to make a voice call, the device typically ‘falls-back’ to a 3G or 2G network.
USNs unify multiple node functions inside one. The USN supports multi-access, GSM, WCDMA, LTE and interworks with Wi-Fi and CDMA. However, certain information critical for monitoring functions flows over a backplane of such node and is not captured by any network monitoring systems, which often creates significant network monitoring challenges.